I’m in the middle of the series of blogs on parallel pumping. We can’t ignore the efficiency of variable frequency drives and motors when looking …
HVAC Hydronic System: Parallel Pumps and Standby Capacity
Giving up the 100% standby pump is often the major concern when using parallel pumping strategies for hydronic heating and cooling systems. This strategy …
HVAC Hydronic System: Controlling Parallel Variable Speed Pumps
The historical view of parallel pumping was to make sure all the staging points landed on the single constant speed pump curve. This avoided …
HVAC Hydronic System: Parallel Pump Operation and Curves
Parallel pumping in hydronic systems can save energy and construction capital costs. Today we continue the series on parallel pumping where we look at the …
Parallel Pumping: What is it and Why do it
Most hydronic heating and chilled water systems end up with one operating pump and one 100% standby pump. It is easy to understand, and the …
HVAC Hydronic System Variable Speed Pump Operation
I am beginning a series on parallel staged variable speed (VS) pumps. As I write this series, it is important to understand and refer to …
HVAC Hydronic Pumps – Should I Trim the Impeller or Trim with Speed? (Part 2 of 2)
In the last R. L. Deppmann Monday Morning Minutes, I offered a couple of reasons why an engineer would schedule a larger impeller than needed …
HVAC Hydronic Pumps – Should I Trim the Impeller or Trim with Speed? (Part 1 of 2)
Engineers schedule a pump capacity in GPM and head along with the horsepower. The pump manufacturer traditionally trims the impeller from the maximum size, also …
Hydronic Cold Fill Makeup Valve: Keep it Open or Closed?
The cold fill pressure setting in a closed hydronic heating or cooling system is still one of the key problems uncovered when our customer service …
Expansion Tank Air Side Maintenance Schedule
I recently visited a school mechanical room and was asked about the relationship between the makeup pressure reducing valve setting and the expansion tank pressure …